Unique Civil Engineering Features of the Balsam Meadow Pumped-Storage Project

The Balsam Meadow Pumped-Storage Project for the Southern California Edison Company is located in the Sierra Nevada Mountains approximately 55 miles northeast of Fresno, California. The pumped-storage project has several features unique to a system of this type. This includes the utilization of an existing tunnel system, elimination of an upstream surge chamber, a vertical raise-bore power shaft, an underground powerhouse, a downstream surge chamber with a 7,500 ft long tailrace tunnel, and use of several additional tunnels to facilitate construction. The project will utilize the available 1,350 ft of head and the water which is presently being transferred to Shaver Lake by tapping into the existing tunnel, diverting the water into a new forebay and installation of the new hydro-electric facility.